Beater 2316, Deck height vs. CR Options

[groot]

So, finally getting around to building a "beater" engine to develop my race car project (been idle too long). The idea is to build a reliable, decent engine that's not crazy expensive to sort out my car, then put in the expensive engine when the chassis is ready. I will only use race fuel with this engine.

Basic specs are:

• 96mm JE pistons
• AA Biral cylinders
• 80mm crank, chevy
• 5.4" Chevy rods
• 2.0L heads (Hoffman prepped) 51.3 cc
• 163/86B cam

So, to get ~0.040" deck height, I'll need 0.210" barrels shims (checked this today), but that puts me at a calculated CR of 10.7:1

Now, the question... should I source 0.220" or larger shims to drop the CR at the expense of deck height? A shim of 0.220" will drop the CR to 10.4:1, but raises the deck height to 0.050"

Thoughts?

[HAM Inc]

The case with the pickup tube in it was still a work in progress when the photo was taken. Still had panels yet to glue in place.

The pickup shot shows the way I removed the goofy M8 stud that runs down the stock tube. I also cut off the bottleneck with the o-ring that fits in the case and replaced with a fitted sleeve that seals to the case with Durco.
Inside the black circle you can see one of the two M6 bolt that secures the pickup in place from the outside of the case.

In the photo that shows the rest of the panels epoxied in place you can see that I blocked off the passage between the crank&cam gears tower and the sump. I did this to keep oil from sloshing out of the sump and into the tower during braking. Inside the black circle is the drain opening from the tower.

The other case half was easy to panel up as there was no pickup to work around. I blocked off all of the sump area on it.

I did two engines with this approach and both worked great.